Characterization, selenylation, and antineoplastic effects on HepG2 cells in vitro and in vivo of an arabinofuranan from the fruits of Akebia quinata

Akebia quinata is a traditional medicinal plant distributed in East Asia and its fruits are applicated in food and pharmaceutical fields. Herein, a novel polysaccharide (AQP70-2A) with a molecular weight of 1.49 × 104 Da was isolated from the fruits of A. quinata. Results of the chemical and spectroscopic analysis indicated that AQP70-2A was an arabinofuranan with a backbone mainly consisting of → 5)-α-l-Araf-(1→, →3,5)-α-l-Araf-(1→, and → 2,3,5)-α-l-Araf-(1→, and it also contained two types of branch chains. At the cellular level, AQP70-2A did not show significant antitumor properties, while selenylation significantly made the inhibitory effect of this natural macromolecule on HepG2 cells to be increased. Furthermore, the zebrafish xenograft model confirmed that selenized polysaccharide Se-AQP70-2A effectively blocked hepatocellular carcinoma cells invasion and metastasis. Meanwhile, the inhibition of Se-AQP70-2A on development of intersegmental vessels revealed its antiangiogenic activity.